Rising steam is evidence of a biological "sludge dryer" at work.

Rising water vapor is evidence of a biological “sludge dryer” at work.

In an era of ever-tightening fiscal belts, water management infrastructure is aging.

When the old sludge dryer can’t keep up, people in charge of sewage treatment systems start to look at options.

Make-do strategies may work for some municipal services,  but wastewater isn’t one of them.  A Tuesday without a yard waste pickup isn’t quite the same as a Tuesday without functioning toilets, is it?

But using energy-intensive technologies to drive water out of sludge is expensive.  And when it comes time to replace/upgrade, traditional drying solutions may no longer be the best.

In an eco-sensitive world, energy-intensive dryers are no longer viewed as good options.   Drying beds offer a low-energy alternative.   But beds are only practical where time and space abundant.

A new era and a new kind of sludge dryer

Sludge dryers have been around a long time.  But like cesspools and unlined landfills, the “old ways” are disappearing. Antiquated methods are giving way to more efficient options.  Switching to a biological sludge dryer is one of them.

Biological drying (or biodrying) is also a heat-based technology.  But in this case, the heat is “free,” generated by the enzymatic activity of feeding microbes.

Yes, the fans that maintain the microbial environment need energy.  But those fans aren’t generating and pumping heat. They’re only moving air.   That makes both installation and operating costs very attractive compared to other systems.

The same bio-technology can dry sludge and reduce mass.  Production of an EPA Class A Exceptional Quality (EQ) compost is optional. When managed to meet VAR/PFRP goals, biological drying can also eliminate liming.

The result is volume and weight reduction, plus a “less objectionable” residual. Generators can continue existing land application or landfill programs. Or the processing goal can be production of a market-grade product.

Pre-disposal, biological dryers offer reductions in transportation volumes and tipping fees.

When augmenting incineration facilities, bio-drying can positively impact those operating costs, too.